There is a variant for the Toyota Hilux and the Ford Ranger, and a more generic catch-all: "Shorten wants to tax your ute."

Such specific ads would not work in a TV commercial break or a newspaper splash, but Facebook gives penny-pinching campaign strategists the ability to narrowcast their messages to fans of particular topics, as exposed by the pages they like.

7.30 created a test Facebook page and confirmed it is possible to target ads to users with a "common interest" in Mitsubishi Tritons, or any other popular model. Advertisers have the option to narrow it down further, making it possible to target male Triton fans aged 18-35 in Cairns, for example.

Once published, however, Facebook does not show any detail about how each ad is targeted.

Now bunkered down in their respective campaign headquarters — the Coalition in Brisbane, Labor in Parramatta — political staffers are apparently watching each other's moves, ready to put out spot fires within niche streams of social content.

Seemingly aware the Coalition was targeting the newsfeeds of ute drivers, the Opposition returned fire one day later.

By Thursday, Facebook data shows Labor was running ads such as this one:

"If you just put a message directly from the Coalition, a lot of people — especially swinging voters, who aren't passionate about politics necessarily — aren't going to engage with it. But if you're a passionate ute driver and it's about your ute, that might pique your interest."

But narrowcasting has always come with a caveat. Parties have long accused each other of saying "one thing in north Queensland and another thing in Melbourne" on controversial topics like coal mining.

"Of course you can narrowcast more with social, so you can get one particular message to a certain constituent, especially geographically, and a different message to another. [But] if they become contradictory, you risk looking like a hypocrite," Mr Mitchelmore said.

Author and journalist Niki Savva, who worked for the Coalition during the 2007 Rudd-Howard race, says the attack lines on electric vehicles and emissions standards were a "test case" for the campaign proper.

"In 2016, there was no negative campaign run against Shorten … and I think that Morrison was very keen not to replicate those mistakes," Ms Savva said.

She said the rhetoric about saving tradies' utes was "overcompensating" and probably "backfired", but was evidence of a government testing out various lines to find the killer issue with which to whack the opposition.

Watch this space

We are only able to search political ads so easily thanks to Facebook's recent creation of an Ad Library, in response to calls for greater transparency.

On Friday, the first full day of the campaign, there were 57 live ads on the Liberal Party of Australia page — mostly on cars, share dividends, the budget surplus, tax cuts and negative gearing. Labor's federal page had 12, on cars and the economy.

The data also gives an insight into how the parties are thinking about key states.

Queensland Labor has 43 live ads, with a heavy focus on urging people to get on the electoral roll before the April 18 deadline.

The Queensland branch appears to be making heavy use of location-based targeting. One ad says Nationals MP Ken O'Dowd, whose 1 per cent margin is one of the thinnest in the country, is "obsessed" with importing temporary foreign workers. Another targets George Christensen's trips to the Philippines in 2017 while his electorate struggled with the aftermath of Cyclone Debbie.

By comparison, the NSW and Victorian pages are not running any ads at the moment.

The Ad Library tool has limitations. There is no way to conclusively prove how ads are targeted, though it can often be inferred from the content. Once ads are pulled down, which sometimes happens within hours or days, they are difficult to retrieve unless you took a screenshot.

The ABC is using crowdsourcing to gather everything from texts and robocalls, to memes, to graffiti. The Guardian is running a similar project.

The Australian Electoral Commission has made it clear social media ads need to be publicly authorised by the parties, just like other ads. But not every post needs to include an authorisation, so long as there is one on the page that posts it.

In response to questions from 7.30, a Coalition campaign spokesperson said the party was "making full use of the social media channels available to us in order to best communicate our message to voters".

A Labor campaign spokesperson said the opposition was "reversing the cuts to hospitals, schools and penalty rates in every city, suburb and town in Australia, and we want people to know about it".

"We use a lot of different methods to talk to Australians about our Fair Go Action Plan, including social media."

Facebook Australia has already promised to block Australian election ads purchased overseas during the campaign.

A spokesperson for the tech giant told 7.30 it had developed "dedicated escalation protocols" so the AEC can notify Facebook if it sees ads that breach the Electoral Act.

"When this happens, we will block the content out of respect for local law," the spokesperson said.

Tell us how you've been targeted by political advertising this election